A process plant includes facilities that realize predetermined functions such as tanks, piping, pumps, compressors, and heat exchangers and a process control system that measures or controls states of the facilities and states of raw materials, gases, coolants, and the like flowing in the facilities. Recently, advancements and increases in complexity of such process plants have progressed and the number of facilities which are controlled by the process control system is increasing.
In such a process control system, a simulator for simulating behavior of a plant is often used. For example, Japanese Patent No. 4789277 discloses a simulator that adjusts (tracks) a simulation model from time to time on the basis of actual data (on-line data) of a plant and executes simulation in parallel with operation of the plant using the adjusted simulation model in order to improve calculation accuracy of the simulator. Japanese Unexamined Patent Application, First Publication No. 2009-163507 discloses a simulator that is used to diagnose facilities as well as to predict a process status (also refer to Japanese Patent No. 4524683 and Japanese Patent No. 5212890).